What is Rapoport's rule in simple terms?

Species near the equator often live in narrow areas, while species closer to the poles tend to live across wider areas.

Is the rule universal?

It fits relatively well for land organisms in the Northern Hemisphere but poorly for groups such as marine fishes, so it is seen as a pattern that varies by region and taxon rather than a universal law.

Rapoport's Rule

🔬 Natural Sciences By CampusDown Wiki Editorial Team Last updated October 26, 2026

Rapoport's rule is the biogeographic generalization that the latitudinal ranges of plant and animal species tend on average to become wider from the equator toward the poles, that is, at higher latitudes. George Stevens (1989) named it after observations by the Argentine ecologist Eduardo Rapoport (1975).

Contents

1. Origins and basic observation
2. The climatic variability hypothesis
3. Critiques and meta-analysis
4. FAQ
5. References

Origins and basic observation

In Areography, Rapoport (1975, 1982) systematically analyzed the geographic ranges of species and noted that the ranges of North American mammal subspecies grow larger toward the north. Stevens (1989) extended the observation to trees, molluscs, fishes, amphibians, reptiles and mammals, formulated it as a general rule that species' latitudinal ranges widen at higher latitudes, and named it Rapoport's rule. Stevens (1992, 1996) went on to extend the rule to gradients in elevation and ocean depth.

The climatic variability hypothesis

The leading explanation proposed by Stevens is the climatic variability hypothesis. Because high-latitude regions have large seasonal temperature swings, species living there have evolved to tolerate a wide range of temperatures and can therefore occupy larger areas. The logic matches Janzen's (1967) hypothesis that mountain passes are effectively higher barriers for organisms in the tropics. Sunday, Bates and Dulvy (2011) partly supported the idea with a global analysis showing that the thermal tolerance ranges of ectotherms widen with latitude. Stevens also suggested that the tropics have many narrow-ranged species plus individuals spilling in from surrounding areas, which raises local species diversity.

Critiques and meta-analysis

Rohde, Heap and Heap (1993) reported that the rule does not hold for marine teleost fishes, and Rohde (1996) argued that it is mainly a local phenomenon of high northern latitudes. Colwell and Hurtt (1994) pointed to the possibility of a statistical artifact, showing that randomly placing ranges within a bounded domain can produce similar patterns. In a paper titled Rapoport's rule: Time for an epitaph?, Gaston, Blackburn and Spicer (1998) concluded that it is a pattern limited to some regions and taxa rather than a general rule. A meta-analysis by Ruggiero and Werenkraut (2007) confirmed a weak overall positive trend but found large differences depending on method and region. Gaston (2003) places the debate within the broader study of geographic ranges.

FAQ

What is Rapoport's rule in simple terms?: Species near the equator often live in narrow areas, while species closer to the poles tend to live across wider areas.
Is the rule universal?: It fits relatively well for land organisms in the Northern Hemisphere but poorly for groups such as marine fishes, so it is seen as a pattern that varies by region and taxon rather than a universal law.

Sources reviewed: 2026-10-26

References

Rapoport, E. H. (1975). Areografía: Estrategias Geográficas de las Especies. México: Fondo de Cultura Económica.
Rapoport, E. H. (1982). Areography: Geographical Strategies of Species. Oxford: Pergamon Press.
Stevens, G. C. (1989). The latitudinal gradient in geographical range: How so many species coexist in the tropics. American Naturalist, 133(2), 240–256.
Stevens, G. C. (1992). The elevational gradient in altitudinal range: An extension of Rapoport's latitudinal rule to altitude. American Naturalist, 140(6), 893–911.
Stevens, G. C. (1996). Extending Rapoport's rule to Pacific marine fishes. Journal of Biogeography, 23(2), 149–154.
Janzen, D. H. (1967). Why mountain passes are higher in the tropics. American Naturalist, 101(919), 233–249.
Rohde, K., Heap, M., & Heap, D. (1993). Rapoport's rule does not apply to marine teleosts and cannot explain latitudinal gradients in species richness. American Naturalist, 142(1), 1–16.
Rohde, K. (1996). Rapoport's rule is a local phenomenon and cannot explain latitudinal gradients in species diversity. Biodiversity Letters, 3(1), 10–13.
Colwell, R. K., & Hurtt, G. C. (1994). Nonbiological gradients in species richness and a spurious Rapoport effect. American Naturalist, 144(4), 570–595.
Gaston, K. J., Blackburn, T. M., & Spicer, J. I. (1998). Rapoport's rule: Time for an epitaph? Trends in Ecology & Evolution, 13(2), 70–74.
Gaston, K. J. (2003). The Structure and Dynamics of Geographic Ranges. Oxford: Oxford University Press.
Ruggiero, A., & Werenkraut, V. (2007). One-dimensional analyses of Rapoport's rule reviewed through meta-analysis. Global Ecology and Biogeography, 16(4), 401–414.
Sunday, J. M., Bates, A. E., & Dulvy, N. K. (2011). Global analysis of thermal tolerance and latitude in ectotherms. Proceedings of the Royal Society B, 278(1713), 1823–1830.

Reports and materials that use this theory (Korean)

There are no materials dedicated to this theory yet, but you can search related reports in the CampusDown library (Korean).

Find more reports · Search '라포포트의 법칙' on CampusDown →

Bergmann's RuleWhat Bergmann's rule is: the tendency for warm-blooded animals in colder, higher-latitude regions to be larger, its surface-to-volume explanation, Allen's rule, alternative explanations, debates over its validity, and research on shrinking body size with warming.🔬 Natural Sciences Species–Area RelationshipWhat the species–area relationship is: why the number of species rises with area according to a regular rule, the power model and z-values, Preston's theory, island biogeography and the SLOSS debate, and its use and limits in estimating extinctions from habitat loss.🔬 Natural Sciences Island RuleWhat the island rule is: the tendency of large animals to shrink and small animals to grow larger on islands, Foster's 1964 observations, fossil cases of dwarfism, ecological explanations based on resources, predation and competition, and meta-analyses.🔬 Natural Sciences MetapopulationWhat a metapopulation is: a population of local populations linked by dispersal, its origins, the Levins model and equilibrium occupancy, Hanski's incidence function model, fragmentation, extinction debt and metacommunities.🔬 Natural Sciences Competitive Exclusion PrincipleWhat the competitive exclusion principle is: why two species using the same limiting resource in the same way cannot stably coexist, Gause's experiments, Lotka–Volterra models, niches, the paradox of the plankton and coexistence theory.🔬 Natural Sciences

Latest ArticlesView all ›

New guides for college study and assignments (Korean)

This article was last updated on October 26, 2026. It is based on widely recognized original works and textbooks; when citing it in a paper, please check the original sources listed in the references.